Image quality control system for an image processing system

Abstract

An image quality control system for an image processing system for producing an image of high quality by removing noise and mesh-dot components from image input signals representing a scanned original image, the image quality control system comprises a low-pass smoothing filter adapted for removing from image input signals representing a halftone image substantially all of any mesh-dot component, for smoothing the image input signals representing the halftone image, and for producing smoothed output signals representing the smoothed image input signals, a smoothing modulation table for modulating the smoothed output signals of the smoothing filter to produce modulated smoothed output signals, a bandpass edge detect filter for detecting edge component signals of the image input signals, the edge component signals comprising a high frequency component of the image input signals, the edge detect filter producing edge output signals, an edge emphasis modulation table for modulating the edge output signals to produce modulated edge output signals, and means for selecting parameters of the bandpass edge detect filter, the low-pass smoothing filter, the smoothing modulation table, and the edge emphasis modulation table for every image signal such that the modulated edge output signals and the modulated smoothed output signals correspond to the image input signals with the noise and mesh-dot components thereof substantially removed.